Varicella/Chickenpox
Although generally mild, varicella (chickenpox) is a highly contagious virus that can lead to severe illness with complications such as secondary bacterial infections, severe dehydration, pneumonia, central nervous system irregularities and shingles. Once one is infected with the varicella virus it remains in the body for life and may reappear as shingles, particularly in elderly persons.
Infection with varicella during pregnancy can allow the passing of the virus to the fetus, resulting in abnormalities in 2 percent of cases. The fetus can develop scarring of the skin and affected limb(s), limb deformities (hypoplesia), eye damage, low birth weight, brain atrophy (loss of neurons), and mental retardation. The virus sometimes leads to fetal death and/or spontaneous abortion. Some babies infected while still a developing fetus will die in infancy.
Before the varicella vaccine, the U.S. reported an estimated 4 million cases of disease a year, leading to approximately 11,000 hospitalizations and 100 deaths. Historically one out of every 10,000 cases of chickenpox proved fatal with 23 out of every 10,000 cases progressing to pneumonia. A new chickenpox vaccine was licensed in 1995, and incidence of the disease is now declining.
